This term came about through a very popular cartoon of a helmet topping off a pair of boots to signify the veteran with just a short time left in his enlistment and keeping a REALLY low profile, turtle-like, trying to make it out alive. Among VietNam and older veterans a challenge term by which infantrymen recognized each other.

When a veteran infantryman would meet another veteran, the question would be asked: "Are you a turtle?". To which the challenged veteran would have to either reply "You bet your sweet ass I am!" or have to buy the challenging veteran a drink.

a girl that is so hot that you would do anything to sleep with her including biting her turtle head off, which in this circumstance means the initial portion of fecal matter that has peaked its head from the buttocks.